<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<link rel="stylesheet" type="text/css" href="http:///at.alicdn.com/t/font_1867112_xpqdvg7so3d.css"/>
		<style type="text/css">
			#bod{
				width: 100%;
				height: 5000px;
			}
			#nav{
				width: 100%;
				height: 200px;
				background-color: red;
			}
			#sous{
				height: 80px;
				/* background-color: green; */
				margin-top: 50px;
				padding-left: 180px;
				/* position: fixed; */
			}
			#sous>#inp{
				border: solid greenyellow;
				outline: none;
				float: left;
				height: 28px;
				width: 600px;
			}
			#sous>span{
				
				font-size: 31px;
				float: left;
				display: block;
				background-color:#008CFF;
			}
		</style>
	</head>
	<body>
		
		<div id="bod">
			<div id="nav"></div>
			<div id="sous">
				<input type="text" name="" id="inp" value="" />
				<span class="iconfont icon-sousuo" ></span>
			</div>
		</div>
		<script type="text/javascript">
			window.onscroll=function(){
				if(scrollY>=370){
					sous.style.position='fixed';
					sous.style.top='0';
				}else{
					sous.style.position='';
					sous.style.top='';
				}
				
			}
		</script>
	</body>
</html>
